vSAN monitors the performance of each storage device and proactively isolates unhealthy devices. It detects gradual failure of a storage device and isolates the device before congestion builds up within the affected host and the entire vSAN cluster.

When a magnetic disk or flash capacity device fails, vSAN evaluates the accessibility of the objects on the device and rebuilds them on another host if space is available and the Primary level of failures to tolerate is set to 1 or more.

When a flash caching device fails, vSAN evaluates the accessibility of the objects on the disk group that contains the cache device, and rebuilds them on another host if possible and the Primary level of failures to tolerate is set to 1 or more.

When the connectivity between the hosts in the cluster is lost, vSAN determines the active partition and rebuilds the components from the isolated partition on the active partition if the connectivity is not restored.